There is a bit of confusion over what displays are supported via the new MacBook Pro's Thunderbolt 3/USB-C ports. If you don't have a display that uses a Thunderbolt 3/USB-C port— like the new 4K and 5K LG displays being sold exclusively by Apple for the new MacBook Pros— then you'll need an adapter to go from Thunderbolt 3 to whatever I/O your display has (DisplayPort, HDMI, Thunderbolt 2, etc). Something like Apple's Thunderbolt 3 to Thunderbolt 2 adapter, for example. But here's where some users have been confused and accidentally purchased the wrong adapter:Thunderbolt 2 uses the same physical connector as Mini DisplayPort, but Apple's new Thunderbolt 3 to Thunderbolt 2 adapter won't work with DisplayPort displays. So, if you bought the new MacBook Pro and were hoping to use it with an Apple Cinema display or other Mini DisplayPort monitor like this guy, you won't be able to do so with Apple's official adapter.Indeed a couple of Apple support docs for the adapter (here and here) mention the limitation: